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(No Model.) 8 SheetsSheet 1.

RAILWAY SIGNAL SYSTEM.

Patented May 14, 1895.

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(No Model.) 7 I 8 Sheets-Sheet 2. G. L. THOMAS. RAILWAY SIGNAL SYSTEM.

Patented May 14,1895.

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(No Model.) 8 Sheets-Sheet 3.

G. L. THOMAS. RAILWAY SIGNAL SYSTEM.-

" Patented May 14, 1895.

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G. L. THOMAS. RAILWAY SIGNAL SYSTEM.

PatentedMay 14, 1895.

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G. L. THOMAS. RAILWAY SIGNAL SYSTEM.

Patented May 14, 1895.

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RAILWAY SIGNAL SYSTEM. No. 539,164. Patented May 14, 1895.

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GTL. THOMAS.

Patented May 14, 1895.

WIIIIIIF L4 RAILWAY SIGNAL SYSTEM.

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A 8 Sheets-Sheet 8. G L THOMAS RAILWAY SIGNAL SYSTEM.

No. 539,154. Patented May 14, 1895.

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TATES PATENT- Fines.

GEORGE THOMAS, OF BROOKLYN, ASSIGNOR TO THE HASELL PERFEOTED RAILWAYSIGNAL COMPANY, OF NEW YORK, N. Y.

RAILWAY SIGNAL SYSTEM.

SPECIFICATION forming part of- Letters Patent No. 559,154, dated May 14,1895.

Application filed January 26, 1895. Serial No. 536,310. (No model.)

To all whom it may concern.-

Be it known that I, GEORGE L. THOMAS, of Brooklymin the county of Kingsand State of New York, have invented a new and useful Improvement inRailway Signal Systems, of

which the following is a specification.

My invention relates to an'improvementin railway signal systems in whichseries of signals arranged along a track are under the to control of atrain moving along the track to guard against both head and rearcollisions and also against accident resulting from a broken ordisplaced rail.

In-my present system the signals are nor- 5 mally at danger and arereleased and locked against releasing by electric circuits under thecontrol of the train in such a manner that, if the way be clear, thetrain in passing a signal on its right will set the next succeedingsignal on its right to safety, the signal which it is just-passing todanger, will lock the preceding signal on its right, so that itcannot-besetto safety until the train shall have passed the next succeedingsignal on its right and will lock the 'next two successive signals onits left, so that they cannot beturned to safety by a train approachingin the opposite direction. train within two blocks of a given train inadvance of it, moving ip either the same or in the opposite direction,the said given train cannot obtain a clear? signal to advance, nor can afollowing train within two blocks of the given train obtain a clearsignal.

I have furthermore shown, in the present application, the signalapparatus as consisting of a plurality of semaphore arms located oneabove another and operated by a rotary spindle under the control ofelectromagnets 40 and provided with circuit making and breaking devices,the electromagnets and their armatures for controlling the rotarymovement of the spindle in steps at intervals of a third revolutionbeing quite similar to that shown 5 and described in connection with thesignal system patented by Thomas and Seward, No. 508,356, dated November7, 1893.

In the accompanying drawings, Figure 1 is a view in side elevation ofthe signal apparatus, showing the arms in the position to denote danger.Fig. 2 is a similar view show- It follows therefore that, if there be aing the arms in a position to denote safety. Fig. 3 is a similar viewshowing the arms in .is denoted by A, its actuating wheel by a, the

releasing magnets by B, B, B and their arby matures b, b, brespectively.

The semaphore arms are denoted by O, O and are mounted upon suitablepivots c, a so as to be rocked from a horizontal position shown in Fig.1, to a depressed position, shown in Fig. 2. Each ofthe signal blades 0,O is provided with a counterbalance of any well known or approved formsufiicient to return the arm to the horizontal or danger position underthe influence of gravity whenever the arm is left free to swing. The armO has fixed to rotate therewith a mutilated pinion c and the arm 0 hasfixed to rotate therewith a similar mutilated pinion 0 A master wheel Ais fixed on the spindle A to rotate therewith and is provided withmutilated gear; in the present instance ashort gear of two teeth 0. Mapoint on its periphery and at a diametrically opposite point of itsperiphery a short gear of two teeth a 1 The relation of the master wheelA to the mutilated gearpinions c and c is such that the gears o. and aon the master wheel will engage the gear on the pinions c and c as thewheel A is revolved. The wheel A is further provided with laterallyprojecting mutilated rims a a upon oppo- 9 5 site sides of the wheel Aand adapted to receive under them antifriction rollers 0 c on arms a andc fixed to rotate with the mutilated pinions c 0 and their semaphoreblades, for the purpose of retaining the said too semaphore blades apredetermined time in their depressed positions during the revolution ofthe spindle A. The arrangement here shown is such that when the spindleA is released and permitted to move one-third of a revolution from theposition shown in Fig. 1, the master wheel A will simultaneously engageboth of the mutilated gear pinions c and c and will rock the twosemaphore blades 0, G into their depressed position shown in Fig. 2)where they will be held by the engagement of the retaining arms with theretaining rims on the master wheel. When the spindle A is rotated thenext one-third revolution, it will not engage either of the mutilatedgear pinions, or it it does engage the pinion 0 the latter will not beheld in its depressed position but its retaining arm will have passedout of engagement with the guard rim a and it will be free to resume itshorizontal position under counterbalance weight while the arm 0 willstill be retained in its depressed position, thereby throwing the twoarms in the relative position shown in Fig. 3. During the finalone-third revolution of the spindle A, the guard arm of the semaphoreblade G will have passed out of engagement with the retaining rim (1. onthe master wheel A, thereby permitting the blade 0 to resume itshorizontal position while the lower blade C will have remainedundisturbed, thereby leaving the signal in the position shown in Fig. l.v

For purposes of making and breaking the several circuits at the properintervals to produce the required releasing and locking of the signaloperating mechanism, I have provided the spindle A with a series ofeccentric disks; represented in Fig. 4 by D, D, D D D and D in positionto close the several pairs of contact pieces; represented by d, (1, (Z(Z d and 61 respectively. The effect of the closing or opening of theseveral contact pieces will be understood from the explanation of thecircuits to be hereinafter recited.

The signal towers composing each set are represented respectively by Eand E, those on the left hand side of the track (assuming the train tobe moving from the left toward the right as the drawings are read) beingdenoted by E, those on theright hand side being denoted by E. Theelectrical apparatuses in the towers constituting a set areinterconnected. The circuit closing disks and contact pieces,represented in plan in Fig. 4, are those which appear in each of thetowers E. The disks for closing the circuits in the towers E arerepresented respectively by F, F, F F and F and the correspondingcontact pieces byf, 7, f f and f. In other respects the signal actuatingmechanism of the towers E is quite similar to that of the towers E.

For purposes of explanation, I have as sumed a train as occupying theposition of the truck G in Fig. 5 and moving in the direction of thearrow also in the position represented by the truck G, Fig.8, and movingin the direction of the arrow and also in the position shown by thetruck G Fig. 10, and moving in the direction of the arrow. As thedifferent sets of towers E, E are identical in all their essentialfeatures, it will only be necessary to explain in detail the setrepresented in Fig. 5 and then assume a similar arrangement in each ofthe succeeding sets.

Referring to the tower E, there is, in addition to the electromagnets B,13, I3 the circuit closers, contact pieces and signal actuatingmechanism; a main relay II, having an armature h, an auxiliary relay I,having an armature 't', and an auxiliary relay J, having an armaturej.The armature h is at all times in electric communication with the earthby a wire K.

The companion tower E is provided with a main relay H, having anarmature h, an auxiliary relay 1, having an armature t" and an auxiliaryrelay J, having an armatu re j.

The track rails are denoted respectively by M and M. The rails areinterrupted at each set of towers by insulations m and m and areelectrically connected with each other to the left of such insulationsby a wire m having interposed therein a battery m One pole of the relayII is connected by a wire Z extending from the relay through a battery Lat a preceding tower E, thence across the track by a wire Z to one ofthe contact pieces f of the tower E, thence by a wire Z to the armatureh of the main relay ll of that tower, thence by a wire Z and a branchwire Z to a wire Z leading from one of the poles of the relay H to therail M, thence along said rail to the next succeeding set of towers andthence by a wire Z to one of the contact pieces cl of the tower E,thence by a wire Z to the opposite pole of said relay ll from which thetracing of the circuit began.

One pole of the auxiliary relay I is connected by a wire 92 through abattery N at a preceding tower E and wire n with one of the poles of theauxiliary relay J, the circuit continuing from the opposite pole of saidauxiliary relay J through a wire 71 to a contact piece a in position tocontact with the armature h when the latter is closed, the circuitcontinuing thence through the wire K to ground. The opposite pole of theauxiliary relay I is connected by a wire 11, with a contact piece 1L5 inposition to engage the armature h of the relay II of that tower when thesaid armature is closed, the circuit continuing thence through the wireK of that tower to ground and thence completing the circuit through thepoles of the relay I by means of the ground connections. The wire n fromone of the poles of the auxiliary relay I is also connected by a wire awhich crosses the track with one of the contact piecesf of the companiontower E, the circuit continuing thence through the other contact piece fand wire to ground.

One pole of the auxiliary relay J is connected by the wire 17, with thecontact piece n in position to engage the armature hot the relay H ofthat tower when the latter is closed,

as has already been stated, andthe other pole of said auxiliary relay Jis connected through the wire n, battery N, wire 'n,-auxiliary relay Iof the next succeeding tower E, and wire 12 of that tower and contactpiece 11* whichwhen the armature h of the main relay H of .that tower isclosedco'nnects with ground through the wire K.

The armature h, as has already been stated, has a constant groundconnection K and also a constant connection through the wire 0, batteryO and wire 0" with one of the contact pieces at each of the contacts (1d 62 of that tower.

The armaturei of the auxiliary relay I has a constant connection througha wire 0 with a contact piece 0 in position to engage the armaturej ofthe auxiliary relay J when the said armature is open and also by abranch wire 0 with a contact piece 0 in position to engage the armatureh when the latter is closed.

The armaturej has a constant connection through a wire 0 with one of thepoles of the electromagnet B. The opposite pole of said magnet B isconnected with one of the contact pieces at, the other of said contactpieces 01 being connected with the wire 0, as has already been stated.

,One of the poles of the electromagnet B is connected with one of thecontact pieces at (1 the opposite pole of said magnet being connected bya wire 10 with a contact piece 10 in position to engage the armature iwhen the latter is closed.

One pole of the electromagnet B is connected with one of the contactpieces at d, the other pole of said magnet being connected by a wire 19with a contact piece p in position to engage the armature 7; when thelatter is open. One of the contact pieces at d is connected. by a wire kwith ground and the other is connected by a wire g, which crosses thetrack, witha wire-s leading from one pole of the relay J to a contactpiece q in position to engage the armature h in the companion tower Ewhen the latter is closed.

The wire Z leading from one pole of the main relay H is also connectedby a branch wire with one of the contact pieces at d, the other contactpiece at d being connected by a wire g with the line wire Q at the nextpreceding tower E to the rear.

One pole of the relay H in the tower E is connected by a wire o with therail M to the right of the insulation. The opposite pole of saidrelay His connected by a wire Z with the other rail M to the right of theinsulation and by the branch wire Z and its continuation r with one poleof the auxiliary relay 1. It is also connected by a branch wire Z with acontact piece in position to engage the armature h when the latter isclosed, as has been already noted. The same pole of the auxiliary relay1 to which r is connected is also connected by awire r with a contactpiece r in position to engage the relay h when the latter is closed. Theopposite pole ,of said relay 1 is connected by a wire r through abattery R with the line wire Q.

One pole of the auxiliary relay J is connected by a wire 8 with acontact point q in position to engage the armature h when the latter isclosed, and the opposite pole of said relay J is connected with the linewire Q leading to the next succeeding tower E. The armature h isconstantly connected, by a wire s 'through the battery S and wire withone of the contact pieces at each of the contacts fifand f. The othercontact piece at the contactfis connected by a wire .9 with one pole ofthe electromagnet B. The other contact piece at the contact f isconnected by a wire s with one pole of the electromagnet B and the othercontact piece at the contact f is connected by a wire 8 with one pole ofthe electromagnet B The armature h is connected with the earth by'a wireK. The armature 11 is constantly connected by a wire 3 with the otherpole of the electromagnet B. The armature j is constantly connected by awiret witha contact piece t in position to engage the armature 4." whenthe latter is open and by a branch wire t with a contact piece i inposition to engage the armature h when the latter is closed. The otherpole of the electromagnet B is connected by a wire i with a contactpiece 15 in position to engage the armature j when the latter is closed.

The other pole of the electromagnet B is connected by a wire i with acontact piece 25 in position to engage the armature j when the latter isopen.

The main track circuit for energizing and mediate of that tower and thenext succeeding set of towers and the connection m between the rails M,M including the battery m at the said next succeeding set of towers.

Assuming a train to be approaching the set of signals (Fig. 5) as at Gand moving in the direction of the arrow, its effect upon the signal atthe tower E will be as follows:As it bridged the rails M, M intermediateof the set of towers (Fig.5) and a Similar preceding set of towers, itcut out the battery m at the set of towers (Fig. 5) from the main-relayH at the tower E of the preceding set and thereby permitted itsarmatureh to open, as shown at tower E, Fig. 7. Such opening of thearmature h at tower E at the preceding setdeenergized the relay 1 oftower E (Fig. 5) by' breaking the circuit through the battery B (Fig. 5)which held I energized. A circuit corresponding to this circuit may betraced complete from the relay 1 at tower E (Fig. 6) back to tower E(Fig. 5) as followsz-from one pole of relay 1 (Fig. 6) along wire r tocontact 0, through armature h and wire K to ground, from theopposit-e'pole of relay 1 (Fig. 6), along wire 7 through battery B, linewire Q to relay J, through relay J and wire s to contact q, througharmature h and wire K to ground. The opening of the armature t" of relay1, caused by the de-energizing of the latter, completed the circuitthrough the electromagnet B which held the signal to danger and byreleasing the spindle A, permitted it to revolve acne-third revolutionand thereby throw the signal at E (Fig. 5) to safety. The circuit closedby the opening of the armature i" may be traced as follows, rememberingthat the contact pieces at f were closed as shown atf (Fig. 6) when thespindle was released to throw the signal to clear:-from one pole of theelectromagnet B along wire s to armature i, thence to contact 25, thencealong wire I, thence along wire 15 to contact 15 thence along armature hto wire 3 through battery S, along wire 3 to contactf and thence alongwire 5 to the opposite pole of said electromagnet B. The one-thirdrevolution of the spindie of the tower E (Fig. 5) which sets the signalat that tower to clear, at the same time opened the contact at f andthereby de-energized the main relay H in tower E (Fig. 6), viz: the nextsucceeding tower on the left. The circuit-broken by the opening of thecontact f in said tower Emay be traced as follows:frorn one of thecontact pieces at f 4 along wire Z, across the track to battery L,thence along wire Z to the next succeeding tower E (Fig. 6) to one poleof the main relay II, thence from the opposite pole of said relay alongwire Z to contact d, thence along wire Z to wire at to rail M, thenceback to wire Z, to wire Z, to wire Z through relay h to wire Z to theother of the two contact pieces at f at said tower E (Fig. 5). Thede-energizing of the main relay H in tower E of Fig. 6 and theconsequent opening of the armature h has broken the circuit through theelectromagnet B of the said tower E which holds the signals of thattower to danger and which must be energized in order to set them tosafety and has thereby locked the said signal at tower E (Fig. 6) todanger as a header signal.

The circuit last above referred to for energizing the electromagnet B intower E (Fig. 6) may be traced as follows: from one pole of the saidelectromagnet B to the contact 01 from the opposite pole of saidelectromagnet B along wire 0 to armature j, along said armature tocontact 0 thence to wire 0 to contact 0 to armature h, to wire 0,through hattery O and wire 0, back to said contact 61 The opening of thearmature h at tower E (Fig. 6) has further tie-energized the auxiliaryrelay J at tower E (Fig. 6) and relay I at tower E (Fig. 7) and hasthereby locked the signal at tower E (Fig. 7) to caution.

In using the phrase locked at caution, I wish to be understood as sayingthat the signal at towerE (Fig. 7) cannot be set to other position thancaution by a train coming in the opposite direction along the sametrack. This is so for the following reasons; and as preliminary thereto,attention is called to the fact that the electromagnets B and B releasethe spindle when they are de-energized, while the electromagnet Breleases the spindle when it is energized; and further that theelectromagnet B holds the signal at danger; the electromagnet B holdsthe signalat safety and the electromagnet B holds the signal at caution.If therefore a train approaching the tower E (Fig. 7) in the oppositedirection from the train G (Fig. 5, under consideration) opens thearmaturej of the relay J in tower E (Fig. 7) to set the signal to safetyin the manner hereinabove described in connection with the relay I,tower E (Fig. 5), the opening of said armature j will energize theelectromagnet B and the spindle in tower E will be permitted to rotate aone-third revolution, carrying the signal there to safety, but it willnot be arrested at safety because the circuit through the electromagnetB will be broken by the opening of the armature t of the relay I in saidtower E (Fig. 7) thereby permitting the spindle to rotate a secondone-third revolution immediately after the completion of its firstone-third revolution, thereby carrying the signal from safety tocaution, where it will be held because of the energizing of theelectromagnet B of said tower E (Fig. 7) caused by the closing of thecontact at (Z by the circuit closer D as the spindle completes itssecond one-third revolution.

The circuit referred to hereinabove for energizing the electromagnet Bof tower E (Fig. 7) may be traced from one pole of the electromagnet Balong wire 0 to armature j, to contact 0 to wire 0 to contact 0 toarmature h, to wire 0, through battery 0, to wire 0, to contact cl andthence to the opposite pole of said electro magnet B.

The broken circuit referred to above, which ICO leaves the electromagnetB de-energized to permit the spindle to rotate its second onethirdrevolution, may be traced as follows: beginning with one pole of theelectromagnet B, along wire 19, to contact p, across the break toarmature i, to wire 0 to wire 0 to contact 0 to armature h, to wire 0,through battery O,to wire 0, to contact 61 and thence to the other poleof said electromagnet B.

The circuit referred to above which energizes the electromagnet B andhence retains the signal at caution, may be traced as follows:-beginningwith one pole of the electromagnet B along wire 19 to contact 19 toarmature z', to wire 0 to wire 0 to contact 0 to armature h, to wire 0,through battery 0, to wire 0, to closed contact 61 and thence to theother pole of said electromagnet B It follows, therefore, that the trainin the position G (Fig. 5) has set the signal on its right at clear andhas locked the next succeeding signal on its left to danger and thesecond succeeding signal on its left to caution. Attention will now begiven to the efiect which the train in the position G has had upon thesignals to the rear of it, and on the right hand side, to prevent rearend collision. In order to show this effect to advantage, we will as.-sume the train to have advanced past the sets of signals (Figs. 5, 6 and7) and to occupy the position shown at. G approaching the set ofsignals, (Fig. 8.) By .cutting out the bat passed onto the block betweenthe sets of sig-,

nals (represented at Figs. 8 and 9) and this follows as a matter ofcourse because, as I have already shown in connection with tower E (Fig.5) it is necessary to a completion of the circuit through theelectromagnet B, which holds the signal at danger, that the armature hof that tower should be closed.

The circuits whichwhen broken de-energize the electromagnets B and B attower E (Fig. 7) may be traced as follows: from one pole of the magnetB, along wire i to contact F, to armature j, to wire 25 to contact 75 toarmature h, to Wire 8 through battery S, to wire 3 to contact f, to wire5 to the opposite pole of said electro magnet B, from one pole of theelectromagnet B along wire i to contact 25 to armature j, to wire't tocontact 25 to armature h, to wire 8 through battery S, to wire tocontact f to wire 8 to the opposite pole of said magnet B The opening ofthe armature h at tower E (Fig. 7) has also served to lock the precedingsignal on the right, viz: at tower E (Fig. 6) to caution byde-energizing the relay J at said tower and permitting its armature j toopen, for, when the armature j is open, the opening of the armature t"at that tower and the consequent completion of the circuit whichenergizes the electromagnet B of that tower throws the signal to safetyand will at the same time provide a break in the circuit through theelectromagnet B of that tower so that the signal will immediately passfrom safety to caution.

The broken circuit which de-energizes the relay J in tower E of Fig. 6,may be traced as follows: from one pole of said relay along wire 8 tocontact q, to armature h, to wire K, to ground and from the oppositepole of i net B, along wire i to contact i across break, to armature j,to wire 15 to contact t t0 armature h, to wire .9 through battery S,

The opening of the armature h has to wire 8 to contact f, towire s tothe opposite pole of said magnet B.

It remains now to show what the effect upon two signals will be when twotrains approach each other head on and to this end one train may beassumed to be in the position above referred to, viz: at G (Fig. 8)going in the direction of the arrow, and another train in the positionG2 (Fig. 10) and going in the opposite direction. There are two blocksbetween the positions of the two trains referred to and each train, whenin such position, will receive-as it approaches the tower on its right,the train G approaching the tower E (Fig. 8) and the train G approachingthe tower E (Fig. 10)a caution or distant signal, which will indicate tothem' that the next signal ahead is at danger and will permit them tocreep cautiously up to the danger point.

I have already shown what the efiect of the train moving from left toright will beupon the second signal in advance of it at itsleft and howit is that the train coming in the opposite direction can move it onlyto caution and I will point out particularly how it is that the traincoming from right to left has had such an effect upon the signal attower E (Fig. 8) that it can only show caution or distance. The train atG has, in the manner already described, de-energized the relay H oftower E (Fig. 7) and the opening ofits armature h has, in the manneraforesaid, deenergized the relay 1' of tower E, (Fig.8) permitting itsarmature to open and thereby close circuit through the electromagnet B,releasing the signal at tower E (Fig. 8 and permitting it to turnone-third of arevolution,

or to the position of clear. It will not, however, remain in thisposition becausethe relay J of tower E has become de-energized by thetrain at G2 (Fig. 10) coming in the opposite direction and suchdeenergizing of the relay J breaks the-circuit through the electromagnetB, which would otherwise hold the signal to clear to permit the signalto move another step viz: to caution or distance where it is held by theenergizing of the electromagnet B The broken circuit throughelectromagnet B at tower E (Fig. 8) may be traced as follows: from onepole of said electromagnet B, along wire i to contact i across break, toarmature j, to wire 15 to contact 6 to wire .9 through battery S, towire 8 to contact f, to wire .9 to the opposite pole of said magnet B.

The completed circuit which energizes the electromagnet B to hold thesignal at caution, may be traced as follows: from one pole of the magnetB along wire 25", to contact if to armature j, to wire F, to contact 25to armature h, to wire 5 through the battery S, to wire 5 to contact fto wire 8 to the opposite pole of saidmagnet B 1 The relay J at tower E(Fig. 8) has been energized by the train at g approaching in theopposite direction, as aforesaid, in the fol- ITO lowing manner: Thetrain G by cutting out the main relay H, tower E (Fig. 10) andpermitting its armature h to open has broken the circuit through themain relay H of the next succeeding tower E to its rear, which in turnhas (lo-energized the relay J in tower E (Fig. 10) thereby energizingthe electromagnet B of said tower E (Fig. 10) and permitting the signalat that tower to change from danger to safety. The circuits by whichthese results have been attained may be traced between the towers E, E(Fig. 9) and the corresponding towers (Fig. 10) assuming for the momentthat the train G is approaching the set of towers Fig. 9 instead of theset Fig. 10. The opening of the armature h, tower G (Fig. 9) breaks thefollowing circuit through the relay [-1 of Fig. 10, beginning with oneof the poles of the relay H (Fig. 10) along wire Z to contact d, (which,when the signal at tower E, Fig. 10, is at danger, is closed) along wireZ, to wire m to relay 1 to wire Z (at tower E, Fig. 9) to branch wire Z,to wire Z across break, to armature h, to wire Z to contact f to wire Z,across track, through battery L, to wire Z, to the opposite pole of saidrelay H at tower E (Fig. 10).

The opening of the armature h of relay H, at tower E (Fig. 10)de-energizes the relay J at tower E (Fig. 9) by breaking the followingcircuit: From one pole of the relay J at tower E (Fig. 9), along wire12., through battery N, along wire it, through relay I, at tower E (Fig.10), along wire 02. to contact u across break to armature h, to groundwire K, to ground; from the opposite pole of said relay J, tower E (Fig.9), along wire 01 to contact 92 to armature h, to wire K, to ground. Thede-energizing of the relay J at tower E (Fig. 9) permits its armaturejto open and thereby completes circuit through the electromagnet- B ofthat tower in the manner which has been hereinbefore explained, causingthe signal at that tower to turn from danger to clear.

Returning now to the tower E (Fig. 10) with the train G in the positionthere shown, its effect upon the signal of said tower E (Fig. 10) willhave been, as hereinabove explained, to move the signal from danger toclear, where, if there were no train or other hinderance to theoperation of the circuits, it would remain until the said train G2 haspassed it. The turning of the signal at tower E (Fig. 10) from dangerhas cut out the wire Z from the circuit through the relay H of thattower and has cut in the wire g completing the following circuit throughthe batteryR at tower E (Fig. 9): beginning with one pole ofthe relay Hat tower E (Fig. 10), along wire Z and short branch wire, to contact d,to wire g back to towerE (Fig. 9), across the track, to battery R, attower E (Fig. 9), through said battery to wire 0" at said tower, throughrelay Z, to wire T to wire Z through relay h, to wire Z to contact f, towire Z, across track, through battery L,

at tower E (Fig. 9), to wire Z, to the opposite pole of the relay H, attower E (Fig. 10). This circuit made complete through battery R at towerE (Fig. 9), has cut the relay J at tower E (Fig. 8) out of the effect ofthe said battery R, at tower E (Fig. 9), which is the battery reliedupon to energize it, and its armature j, at tower E (Fig. 8), has beenpermitted to open, thereby breaking circuit through the electromagnet Bwhich would tend tohold the signal at clear, permitting the signal topass on from clear to caution, as shown. It therefore follows that twotrains approaching each other on the track will, when they are twoblocks apart, each receive a caution or distance signal, which willindicate to them that there is danger ahead and under this signal theymay be permitted to creep slowly up to the intermediate danger signal orto any suitable point where a shunttrack is located for purposes ofpassing. Finally, after a train has passed a signal. on its left, thatsignal will be prevented from going either to clear or caution, untilthe train shall have passed away from that signal onto the next.succeeding signal section. If this were not so, it would have the effectof giving a following train the caution signal at the third precedingset of signals in the same manner that the train approachingin theopposite direction gave such train the caution signal as abovedescribed, so that the following train would be stopped at a dangersignal, an entire section behind the train in advance, while theintention is that the following train shall be stopped at the dangersignal adjacent to l or at the end of the block on which the obstructionis; e. 9., while the main relay ll (Fig. 8) signal E, is open, thecircuit between the relays J and I (Figs. 7 and 8) is intact, therebypreventing the signal E (Fig. 7) from going to clear or caution whilethe train is in the position at G, going in the direction of the arrow.This is accomplished as follows: As soon as the signal at the. tower E(Fig. 8) moves from danger, it rotates the circuit closer F intoposition to close the contact pieces at f, completing the circuit asfollows: from earth, tower E (Fig. 7), through wire K,to armature h, tocontact of, through wire m to relay J, through relay J to wire 91', tobattery N, along wire it, to relay I at tower E (Fig. 8), through saidrelay to wire it, to branch wire it, across track to contact f andthence along wire 70, to ground; thus completing the circuit through thesaid relays J, tower E (Fig. 7) and relay I, tower E (Fig. 8).

I have already shown that it was necessary for the armature j to be opento complete the circuit through the electromagnet B to send the signalto clear.

\Vhat I claim is- 1. A block signal system, comprising series of signalsarranged along a track in interconnected sets, electric circuits underthe control of a train moving along the track to control the movementsof the signals, the said electric circuits being arranged to hold thesignals normally at danger, means controlled by the train for turningthe signals to safety when the track is free and circuit breakers andclosers controlled by certainof said electric circuits to prevent aplurality of signals in advance of a train and a plurality of signals tothe rear of a train from being turned to safety by an approaching trainwhen the track is not free, substantially as set forth.

2. A block signal system, comprising series of signals arranged alongatrack in interconnected sets, electric circuits under the control of atrain moving along the track to control the movements of the signals,the said electric circuits being arranged to hold the signals normallyat danger, means controlled by the train for turning the signals tosafety when the track is free and circuit breakers and closers controlled by certain of said electric circuits to preventa plurality ofsignals both in advance and to the rear of a train from being set tosafety when the track is not free and at the same time permitting asignal in advance and also to the rear to be set at caution or distantby an approaching train, substantially as set forth.

3. A block signal system, comprising series of signals arranged along atrack in interconnected sets, insulated track sections corresponding tothe number of sets of signals, a main track circuit, including'the railsof one of the insulated track sections, a battery having one of itspoles connected with one of the said rails and its opposite pole withthe other of said rails and a relay at one of the members of a set ofsignals, and electric circuits connecting the individual members of aset of signals and the adjacent sets of signals and under the control ofsaid main track circuit to display the proper signals when a train ismoving ineither direction along any of the insulated track sections,substantially as set forth.

4. A block signal system, comprising series of signals, arranged alongatrack in interconnected sets, electric circuits connecting the severalsets and members of a set to control the movements of the signals, theelectric circuits at each member of a set of signals including a mainand two auxiliary relays for making and breaking the circuits and atrackcircuit for each set of signals including the main relay of one memberof the set for placing the signals under the control of a train movingalong the track, substantially as set forth.

5. A blocksignal system, comprising series of signals arranged along atrack, each signal comprising a plurality of reciprocating armsconnected to move together throughout a portion of their movement andfree to move independently of one another throughout another portion oftheir movement, means for actuating the arms to give the properinformation, and electric circuits under the control of a train movingalong the track to release the signal actuating mechanism at the properintervals, substantially as set forth.

GEORGE L. THOMAS. -Witnesses:

FREDK. K. HAYNES, GEORGE BARRY.

